In a radar device equipped with an array antenna in which antennas are disposed at equal intervals, there has hitherto been a technique of obtaining reception results by use of virtual antennas of which the number exceeds the number of the actual antennas in a way that performs holographic synthesization of transmission/reception results while switching over the antennas used as transmission antennas (refer to, e.g., Patent documents 1 through 4).
Further, in the radar device such as a synthetic aperture radar (SAR) utilizing adaptive antennas, a technique of restraining influence of interference waves having correlativeness with desired waves is exemplified by a processing technique based on a space averaging method (space smoothing method). This space averaging process is a technique of restraining a degree of a cross-correlation by weighted-averaging correlation values between waves that are obtained by shifting reception positions in parallel while taking account of such a point that a phase relation of the waves having the correlativeness becomes different in the reception position. For example, Patent documents 5-8 disclose the space averaging process in the synthetic aperture radar device.
[Patent document 1] Japanese Patent Laid-Open Publication No. 2004-198312
[Patent document 2] Japanese Patent Laid-Open Publication No. 2005-195491
[Patent document 3] Japanese Patent Laid-Open Publication No. 2006-91028
[Patent document 4] Japanese Patent Laid-Open Publication No. 2006-98181
[Patent document 5] Japanese Patent No. 3678946
[Patent document 7] Japanese Patent Laid-Open Publication No. 2001-194454
[Patent document 8] Japanese Patent Laid-Open Publication No. 2002-181930